LOS ANGELES (AP) — A recent study by the U.S. Department of Agriculture found sales at farmers markets nationwide have declined — and the drop is particularly pronounced in Southern California, long a leader in the market movement.

Sales in Los Angeles County dropped by almost 43 percent in inflation-adjusted dollars from 2007 to 2012, according to the USDA.

Total annual revenues in Southern California dropped from $4.2 million to $2.3 million over the same period.

Farmers and market managers have been concerned for several years now that the number of markets has grown faster than the number of farmers to supply them and shoppers to buy from them, the Los Angeles Times reports.

Total revenue in all markets nationwide declined 1 percent in inflation-adjusted dollars from 2007 to 2012. The number of farmers markets grew at a rate of 17 percent from 2002 to 2007, but the rate has slowed to 5.5 percent per year since.

Many boroughs and communities want a farmers market because they attract food traffic, Rodgers said.

"I fully support the principles behind Senate Bill 1: to defeat efforts by the president and Congress to undermine vital federal protections that protect clean air, clean water and endangered species," Newsom said in a written statement.